Re: Question on workqueue: Manually break affinity on hotplug

From: Peter Zijlstra
Date: Thu Jan 14 2021 - 04:13:20 EST


On Thu, Jan 14, 2021 at 08:03:23AM +0000, Zhang, Qiang wrote:
> Hello Peter
>
> Excuse me, I have some questions for you, about a description of this change:
>
> ''Don't rely on the scheduler to force break affinity for us -- it will
> stop doing that for per-cpu-kthreads."
>
> this mean when cpuhotplug, scheduler do not change affinity for per-cpu-kthread's task, if we not active setting affinity?
> but if per-cpu-kthread's task is not run state, when wake up, will reset it's affinity, this is done automatically.
>
> or is it, this place modified to fit the new one hotplug mechanism which
> ("sched/hotplug: Consolidate task migration on CPU unplug")?

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https://lkml.kernel.org/r/20201218170919.2950-1-jiangshanlai@xxxxxxxxx
https://lkml.kernel.org/r/20201226025117.2770-1-jiangshanlai@xxxxxxxxx
https://lkml.kernel.org/r/20210111152638.2417-1-jiangshanlai@xxxxxxxxx
https://lkml.kernel.org/r/20210112144344.850850975@xxxxxxxxxxxxx